Subcutaneous self attaching injection port with integral fasteners

ABSTRACT

A self attaching injection port has integral fasteners extending from the housing, fixed relative thereto. The fasteners include one way fasteners, such as formed by a plurality of axially spaced concentrically aligned frustroconical annular flanges. The injection port is self attaching upon the surgeon applying a distal force to the injection port housing, causing the fasteners to penetrate the tissue, engaging the tissue to hold the injection port in place.

RELATED APPLICATIONS

[0001] This application claims the priority of provisional patentapplication Ser. No. 60/478,763, titled Fluid Injection Port ForAdjustable Gastric Band, filed on Jun. 16, 2003, the disclosure of whichis incorporated herein by reference. This application also incorporatesby reference the following co-pending United States Patent Applicationsfiled of even date herewith: application Ser. No.______ (SubcutaneousInjection Port For Applied Fasteners, inventors: Conlon and Hunt); andapplication Ser. No.______, (Subcutaneous Self Attaching Injection PortWith Integral Moveable Retention Members, inventors: Conlon, Byrum,Hunt, Nuchols and Schulze).

TECHNICAL FIELD

[0002] The present invention relates in general to surgicallyimplantable fluid injection ports, and is particularly directed tofasteners and methods for fastening subcutaneous peripherally attachedports. The invention will be specifically disclosed in connection withinjection ports used with adjustable gastric bands, although thefasteners of the present invention may be used with many differentsubcutaneuosly attached devices, including injection ports used forvascular access such as the infusion of medications and blood draws.

BACKGROUND OF THE INVENTION

[0003] Injection ports are placed beneath the skin of a body forinjecting fluids into the body, such as for infusing medication, blooddraws, and many other applications, including adjustable gastric bands.Since the early 1980s, adjustable gastric bands have provided aneffective alternative to gastric bypass and other irreversible surgicalweight loss treatments for the morbidly obese. The gastric band iswrapped around an upper portion of the patient's stomach, forming astoma that restricts food passing from an upper portion to a lowerportion of the stomach. When the stoma is of the appropriate size, foodheld in the upper portion of the stomach provides a feeling of fullnessthat discourages overeating. However, initial maladjustment or a changein the stomach over time may lead to a stoma of an inappropriate size,warranting an adjustment of the gastric band. Otherwise, the patient maysuffer vomiting attacks and discomfort when the stoma is too small toreasonably pass food. At the other extreme, the stoma may be too largeand thus fail to slow food moving from the upper portion of the stomach,defeating the purpose altogether for the gastric band.

[0004] In addition to a latched position to set the outer diameter ofthe gastric band, adjustability of gastric bands is generally achievedwith an inwardly directed inflatable balloon, similar to a bloodpressure cuff, into which fluid, such as saline, is injected through afluid injection port to achieve a desired diameter. Since adjustablegastric bands may remain in the patient for long periods of time, thefluid injection port is typically installed subcutaneously to avoidinfection, for instance in front of the sternum. Adjusting the amount offluid in the adjustable gastric band is achieved by inserting a Huberneedle through the skin into a silicon of the injection port. Once theneedle is removed, the septum seals against the hole by virtue ofcompressive load generated by the septum. A flexible conduitcommunicates between the injection port and the adjustable gastric band.

[0005] The traditional surgical technique for securing a fluid injectionport developed for vascular uses has been applying sutures through aseries of holes spaced about a peripheral base flange. While generallyeffective, suturing often proves to be difficult and time consuming,even more so with adjustable gastric band which are intended for themorbidly obese. A significant thickness of fat tissue may underlie theskin, causing difficulties as the surgeon attempts to apply sutures todeeply recessed tissues (e.g., 5-10 cm) to secure the port, oftenrequiring 10-15 minutes to complete. Further, if the injection port isnot sutured properly, the port may flip over, making subsequentinjections difficult or impossible.

[0006] Recently, a surgical stapler has been described in a Germanpatent application No. 197 51 791.9 to Pier wherein a hat-shapedinjection port includes tangentially aligned linear grooves spacedaround its perimeter. A pair of holes in each linear groove receives atraditional bent wire staple. A stapler holds the staples in place andhas downwardly moving forming member that presses upon the shoulders ofeach staple. Due to the position of the holes in the linear groove,pointed ends of the staple are deformed inwardly to grip underlyingtissue.

[0007] This Pier stapler thus attaches the staples through a deformationthat may prove difficult to release should the initial placement beundesirable or removal of the gastric band be appropriate. Further,because the device must permanently deform a multiplicity of stainlesssteel or titanium staples, a more complicated mechanism is required toprovide the surgeon with enough mechanical advantage to form the stapleseasily. The Pier injection port also requires a custom stapler handlethat is not useful for any other purpose, which may be an undesirableexpense for surgeons who do not perform numerous placements of the Pierinjection port.

[0008] While a custom stapler for an injection port may have advantagesover suturing, such as the time required to accomplish the attachment,it is believed that other approaches to attaching an injection port mayhave additional advantages or features not provided by traditionalsuturing or a stapler using bent wire staples.

[0009] Consequently, a significant need exists for a fluid injectionport suitable for subcutaneous attachment that is quickly attachable yetis secure over a long period of time.

BRIEF SUMMARY OF THE INVENTION

[0010] As described herein, there is provided an injection port forinjecting fluids into a body. The port includes a housing for placementbeneath the skin of the body, and means for receiving a needle. Anattachment mechanism is provided which is configured to engage tissuesurrounding the housing to retain the housing in place. The attachmentis integrally attached to and fixed relative to the housing. A pluralityof fasteners including retention members in the form of frustroconicalflanges which function as one-way fasteners to resist withdrawal of thefasteners and resist unwanted movement of the injection port.

BRIEF DESCRIPTION OF THE DRAWINGS

[0011] The accompanying drawings incorporated in and forming a part ofthe specification illustrate several aspects of the present invention,and together with the description serve to explain the principles of theinvention. In the drawings:

[0012]FIG. 1 is a diagrammatic drawing showing an injection portconstructed in accordance with the present invention, connected to anadjustable gastric band wrapped around an upper part of a stomach.

[0013]FIG. 2 is a side view of the injection port shown in FIG. 1.

[0014]FIG. 3 is an enlarged, fragmentary side view of the injection portshown in FIG. 1.

[0015] Reference will now be made in detail to the present preferredembodiment of the invention, an example of which is illustrated in theaccompanying drawings.

DETAILED DESCRIPTION OF AN EMBODIMENT OF THE PRESENT INVENTION

[0016] Referring now to the drawings in detail, wherein like numeralsindicate the same elements throughout the views, FIG. 1, adjustablegastric band 10 is shown wrapped around an upper portion of stomach 12,kept in place by attaching the two ends together and extending portion14 of the stomach 12 over adjustable gastric band 10 by suturing portion14 to the stomach. One end of flexible conduit 16 is in fluidcommunication with the internal cavity of the balloon (not shown), withthe other end being in fluid communication with an internal cavity ofinjection port 18. At the time adjustable gastric band 10 is implantedaround a portion of the stomach, remote injection port 18 is alsoimplanted at a suitable location, usually within the rectus sheaths, fortranscutaneous access via a Huber needle.

[0017] As is well known, injection port 18 includes housing 20 havingannular flange 22 extending outwardly from one end. Nipple 24 is influid communication with the internal cavity defined by housing 20, towhich flexible conduit 16 is attached at some point in the procedure,typically after injection port 18 has been implanted. Fluid is added toor removed from the interior cavity of injection port 18 by inserting aHuber needle percutaneously into silicone septum 26 of the injectionport 18. Although septum 26 is made of silicon, the means of theinjection port for receiving a needle includes any structure configuredto self seal after puncture with a non-coring needle.

[0018] Although a specific configuration for injection port 18 isdisclosed herein, there are many suitable configurations which may beused in conjunction with the present invention.

[0019] Referring also to FIGS. 2 and 3, injection port 18 includesintegral fasteners 28 extending distally from housing 20. Fasteners 28are disposed through circumferentially spaced holes 30 (see FIG. 3)formed in flange 22 of housing 20. The teachings of this invention maybe practiced with a smaller flange, or no flange, such as may beaccomplished by forming recesses in the side of housing 20 surroundingholes formed through the base. Three fasteners 28 are effective toprevent injection port 18 from flipping over after implantation, such asdue to passive or induced movements of the patient. However, the presentinvention is not limited to the use of three fasteners, and one or morefasteners may be used.

[0020] The integral fasteners 28 illustrated in FIGS. 1-3 are one wayfasteners. As used herein, a one way fastener is one which is configuredto be inserted into and engage the fascia or other layer, and resistwithdrawal therefrom. Although there are many different structures whichcan provide such one way functionality, such as outwardly extendingaxially and circumferentially spaced fingers, the one way function ofthe embodiment of fasteners 28 illustrated results from a plurality offrustroconical annular flanges 32 axially spaced along shaft portion 34.Tip 36, which is illustrated with inclined surfaces, is formed at thedistal end of shaft portion 34, with head portion 38 disposed at theother end. It is noted that tip 36 may have any shape, although a shapeconfigured to facilitate penetration of the fascia or other layerreduces the force necessary to deploy/implant injection port 18.

[0021] Flanges 28 could alternatively be flat spaced apart flanges,presenting resistance to withdrawal due to the nature of the tissue, butalso presenting increased resistance to insertion than with therearwardly sloping surfaces of the frustroconical shape.

[0022] In the embodiment illustrated, head portion 38 is larger thanhole 30 and thus configured not to pass through the opening 30. Prior todeployment/implantation of injection port 18, fasteners 28 are attachedto housing 20 integrally by inserting them through holes 30. Flanges 32may be sufficiently deformable to yield inwardly when passed throughhole 30. Additionally flanges 32 may be discontinuous about theirrespective circumferences, such as having a slot extending the length ofshaft 34. Flange 32 a retains fastener 28 in hole 30 attached to andfixed relative to housing 20, flange 32 a being axially spaced fromlower surface 38 a of head portion 38 a distance sufficient for flange32 a to expand after being pushed through hole 30, and engage lowersurface 22 a of flange 22 adjacent hole 30, thereby resulting infasteners 28 being integral with injection port 18 prior to deployment.There may be radial clearance between hole 30 and shaft portion 34 oraxial clearance between lower surface 38 a and flange 32 a.

[0023] Although fasteners 28 may be attached to injection port 18 at anypoint prior to or at the time of deployment, it is contemplated thatinjection port 18 will be provided to the surgeon with the integralfasteners 28 pre-attached, as a sterilized assembly.

[0024] Implantation of self attaching injection port 18 is accomplishedby locating injection port 18 in the desired location and applying adistal force to housing 20, or even head portions 38, of injection port18 thereby causing tips 36 of fasteners 28 to engage the adjacenttissue, penetrating fat layer 40 and fascia layer 42 in theillustration. The parallel angles of frustroconical flanges 32 towardhead portion 38 allow fasteners 28 to penetrate and advance through fatlayer 40 and fascia layer 42, and to lock thereagainst to resistwithdrawal.

[0025] Operating as concentric, axially spaced locking rings, flanges 32retain injection port 18 in position.

[0026] Fastener 28 may be made of any suitable medically compatiblematerial having sufficient resilience and strength to perform asdescribed herein, such as polycarbonate, polystyrene, or any suitablepolymer. The quantity, spacing, and dimensions of flanges 32 may be anyquantity, spacing and dimensioning as are suitable. By way of exampleonly, the center to center distance of flanges 32 may be 3 mm, thethickness (at the shaft) may be 1 mm, and the diameter may be 3 mm, withthe shaft 5 mm long.

[0027] In summary, numerous benefits have been described which resultfrom employing the concepts of the invention. The foregoing descriptionof one or more embodiments of the invention has been presented forpurposes of illustration and description. It is not intended to beexhaustive or to limit the invention to the precise form disclosed.

[0028] Obvious modifications or variations are possible in light of theabove teachings. For example, one or more fasteners with one or morefrustroconical flanges may be installed through on into appropriatelyshaped openings in the injection port at the time of implantation, suchas by locating the injection port in the appropriate position in thebody and inserting the fasteners through the openings.

[0029] The one or more embodiments were chosen and described in order tobest illustrate the principles of the invention and its practicalapplication to thereby enable one of ordinary skill in the art to bestutilize the invention in various embodiments and with variousmodifications as are suited to the particular use contemplated. It isintended that the scope of the invention be defined by the claimsappended hereto.

What is claimed is:
 1. An injection port for injecting fluids into abody, said port comprising: a. a housing for placement beneath the skinof the body, said housing including means for receiving a needle; b. anattachment mechanism configured to engage tissue surrounding saidhousing so as to retain said housing in place, said mechanism beingintegrally attached to and fixed relative to said housing.
 2. The portof claim 1, wherein said attachment mechanism is configured such that byapplying a distal force to said housing, said attachment mechanism willengage said tissue so as to retain said housing.
 3. The port of claim 1,wherein said attachment mechanism includes at least one fastenerextending distally from said housing.
 4. The port of claim 3, where insaid at least one fastener comprises a respective distal tip which isconfigured to penetrate said tissue.
 5. The port of claim 3, whereinsaid at least one fastener comprises at least one outwardly extendingflange spaced from said housing.
 6. The port of claim 5, wherein said atleast one flange comprises a plurality of spaced apart flanges.
 7. Theport of claim 5 wherein said at least one flange has a frustroconicalshape.
 8. The port of claim 3 wherein said at least one flange isdiscontinuous.
 9. The port of claim 3, wherein said at least onefastener comprises at least one outwardly extending finger spaced fromsaid housing.
 10. The port of claim 9, wherein said at least one fingercomprises a plurality of spaced apart fingers.
 11. The port of claim 3,further comprising a respective opening for each of said at least onefastener, said at least one fastener being disposed through said hole.12. The port of claim 11, wherein said housing includes an annularflange extending proximal one end of said housing, said respectiveopening being formed in said annular flange.
 13. A method of deployingan injection port for injecting fluids into a body, said methodcomprising the steps of: a. providing an injection port comprising: i. ahousing for placement beneath the skin of the body, said housingincluding means for receiving a needle; ii. an attachment mechanismconfigured to engage tissue surrounding said housing so as to retainsaid housing in place, said mechanism being integrally attached to andfixed relative to said housing; b. locating said attachment mechanismadjacent said tissue; and c. penetrating the tissue with said attachmentmechanism by applying a distal force to said housing.
 14. The method ofclaim 13, wherein said attachment mechanism includes at least onefastener extending distally from said housing.
 15. The method of port ofclaim 14, where in said at least one fastener comprises a respectivedistal tip which is configured to penetrate said tissue.
 16. The methodof claim 14, wherein said at least one fastener comprises at least oneoutwardly extending flange spaced from said housing.
 17. The method ofclaim 16, wherein said at least one flange comprises a plurality ofspaced apart flanges.
 18. The method of claim 16 wherein said at leastone flange has a frustroconical shape.
 19. The method of claim 14,wherein said at least one fastener comprises at least one outwardlyextending finger spaced from said housing.
 20. The method of claim 14,wherein said housing includes an annular flange extending proximal oneend of said housing, said annular flange comprising a respective openingfor each of said at least one fastener, each of said at least onefastener being disposed through said hole.
 21. A method of deploying aninjection port for injecting fluids into a body, said method comprisingthe steps of: a. providing an injection port comprising: i. a housingfor placement beneath the skin of the body, said housing including meansfor receiving a needle; ii. said housing comprising a base having afirst surface and a second surface, said base including at least oneopening extending through said base from said first surface to saidsecond surface; b. providing at one fastener comprising: i. a shafthaving a first and second end; ii. at least one flange extendingoutwardly from said shaft, said at least one flange being spaced fromsaid first end; c. locating said second surface adjacent tissue of thebody; and c. securing said injection port adjacent said tissue byinserting said at least one fastener through said at least one openingso as to engage the tissue disposed adjacent said second surface withsaid at least one flange.
 22. The method of claim 21, wherein said atleast one flange comprises a plurality of flanges spaced apart from eachother axially along said shaft.
 23. The method of claim 22, wherein saidplurality of flanges comprise frustroconical annular flanges.
 24. Themethod of claim 21, wherein said at least one flange has afrustroconical shape.